// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_VIEWS_CONTROLS_BUTTON_MENU_BUTTON_H_
#define UI_VIEWS_CONTROLS_BUTTON_MENU_BUTTON_H_

#include <string>

#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "base/strings/string16.h"
#include "base/time/time.h"
#include "ui/views/background.h"
#include "ui/views/controls/button/label_button.h"

namespace views {

class MenuButtonListener;

////////////////////////////////////////////////////////////////////////////////
//
// MenuButton
//
//  A button that shows a menu when the left mouse button is pushed
//
////////////////////////////////////////////////////////////////////////////////
class VIEWS_EXPORT MenuButton : public LabelButton {
public:
    // A scoped lock for keeping the MenuButton in STATE_PRESSED e.g., while a
    // menu is running. These are cumulative.
    class VIEWS_EXPORT PressedLock {
    public:
        explicit PressedLock(MenuButton* menu_button);
        ~PressedLock();

    private:
        base::WeakPtr<MenuButton> menu_button_;

        DISALLOW_COPY_AND_ASSIGN(PressedLock);
    };

    static const char kViewClassName[];

    // How much padding to put on the left and right of the menu marker.
    static const int kMenuMarkerPaddingLeft;
    static const int kMenuMarkerPaddingRight;

    // Create a Button.
    MenuButton(const base::string16& text,
        MenuButtonListener* menu_button_listener,
        bool show_menu_marker);
    ~MenuButton() override;

    bool show_menu_marker() const { return show_menu_marker_; }
    void set_menu_marker(const gfx::ImageSkia* menu_marker)
    {
        menu_marker_ = menu_marker;
    }
    const gfx::ImageSkia* menu_marker() const { return menu_marker_; }

    const gfx::Point& menu_offset() const { return menu_offset_; }
    void set_menu_offset(int x, int y) { menu_offset_.SetPoint(x, y); }

    // Activate the button (called when the button is pressed). |event| is the
    // event triggering the activation, if any.
    bool Activate(const ui::Event* event);

    // Returns true if the event is of the proper type to potentially trigger an
    // action. Since MenuButtons have properties other than event type (like
    // last menu open time) to determine if an event is valid to activate the
    // menu, this is distinct from IsTriggerableEvent().
    virtual bool IsTriggerableEventType(const ui::Event& event);

    // Overridden from View:
    gfx::Size GetPreferredSize() const override;
    const char* GetClassName() const override;
    void OnPaint(gfx::Canvas* canvas) override;
    bool OnMousePressed(const ui::MouseEvent& event) override;
    void OnMouseReleased(const ui::MouseEvent& event) override;
    void OnMouseEntered(const ui::MouseEvent& event) override;
    void OnMouseExited(const ui::MouseEvent& event) override;
    void OnMouseMoved(const ui::MouseEvent& event) override;
    void OnGestureEvent(ui::GestureEvent* event) override;
    bool OnKeyPressed(const ui::KeyEvent& event) override;
    bool OnKeyReleased(const ui::KeyEvent& event) override;
    void GetAccessibleState(ui::AXViewState* state) override;

protected:
    // Paint the menu marker image.
    void PaintMenuMarker(gfx::Canvas* canvas);

    // Overridden from LabelButton:
    gfx::Rect GetChildAreaBounds() override;

    // Overridden from CustomButton:
    bool IsTriggerableEvent(const ui::Event& event) override;
    bool ShouldEnterPushedState(const ui::Event& event) override;
    void StateChanged() override;
    void NotifyClick(const ui::Event& event) override;

    // Offset of the associated menu position.
    gfx::Point menu_offset_;

private:
    friend class PressedLock;

    // Increment/decrement the number of "pressed" locks this button has, and
    // set the state accordingly.
    void IncrementPressedLocked();
    void DecrementPressedLocked();

    // Compute the maximum X coordinate for the current screen. MenuButtons
    // use this to make sure a menu is never shown off screen.
    int GetMaximumScreenXCoordinate();

    // We use a time object in order to keep track of when the menu was closed.
    // The time is used for simulating menu behavior for the menu button; that
    // is, if the menu is shown and the button is pressed, we need to close the
    // menu. There is no clean way to get the second click event because the
    // menu is displayed using a modal loop and, unlike regular menus in Windows,
    // the button is not part of the displayed menu.
    base::TimeTicks menu_closed_time_;

    // Our listener. Not owned.
    MenuButtonListener* listener_;

    // Whether or not we're showing a drop marker.
    bool show_menu_marker_;

    // The down arrow used to differentiate the menu button from normal buttons.
    const gfx::ImageSkia* menu_marker_;

    // If non-null the destructor sets this to true. This is set while the menu is
    // showing and used to detect if the menu was deleted while running.
    bool* destroyed_flag_;

    // The current number of "pressed" locks this button has.
    int pressed_lock_count_;

    // True if the button was in a disabled state when a menu was run, and should
    // return to it once the press is complete. This can happen if, e.g., we
    // programmatically show a menu on a disabled button.
    bool should_disable_after_press_;

    base::WeakPtrFactory<MenuButton> weak_factory_;

    DISALLOW_COPY_AND_ASSIGN(MenuButton);
};

} // namespace views

#endif // UI_VIEWS_CONTROLS_BUTTON_MENU_BUTTON_H_
